"We know that South Carolina threaten secession IF Lincoln was elected. Everyone assumes that this was over the slavery issue. But when Fort Sumter was fired upon the Northern rally cry was to "Preserve the Union". Freeing the Slaves as we know did not become a War aim until later in the war, when the Northern people grew weary of the War to preserve the Union."
Been saying this for a couple years now. The real issue of the war was power for Lincoln, preserving the Union was an excuse for him to consolidate his power. Slaves-- the North didn't give a rip about them as long as the free blacks and slaves were kept in the South.
Sources: Mostly using info posted on this board!!!!